commit 2aa39889c463195a0dfe2aff9fad413139c32a4f upstream Commit 3ea566422cbd ("can: isotp: sanitize CAN ID checks in isotp_bind()") checks the given CAN ID address information by sanitizing the input values. This check (silently) removes obsolete bits by masking the given CAN IDs. Derek Will suggested to give a feedback to the application programmer when the 'sanitizing' was actually needed which means the programmer provided CAN ID content in a wrong format (e.g. SFF CAN IDs with a CAN ID > 0x7FF). Link: https://lore.kernel.org/all/20220515181633.76671-1-socketcan@xxxxxxxxxxxx Suggested-by: Derek Will <derekrobertwill@xxxxxxxxx> Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- net/can/isotp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/can/isotp.c b/net/can/isotp.c index fb179a333784..902cb61b6495 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -1140,10 +1140,15 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) if (rx_id & CAN_EFF_FLAG) rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK); else rx_id &= CAN_SFF_MASK; + /* give feedback on wrong CAN-ID values */ + if (tx_id != addr->can_addr.tp.tx_id || + rx_id != addr->can_addr.tp.rx_id) + return -EINVAL; + if (!addr->can_ifindex) return -ENODEV; lock_sock(sk); -- 2.34.1